In typical prior art automatic fruit sorting apparatus, optical sensors inspect each moving piece of fruit and generate a reject signal in response to the presence of a cull. The moving fruit to be sorted are carried on singulator conveyors, typically 3 or more, parallel disposed, each of which carry the fruit in single file from the loading chutes. Each singulator conveyor comprises rollers rotatably mounted to chain drive means. The rollers may be adjustably spaced along the chains in accordance with the size of fruit to cause each piece of fruit to be carried between adjacent rollers.
After the surfaces of the fruit are scanned by the optical sensors, and responsive signals generated in accordance with the scan, typically by means of a line scanning camera, ejection or diversion mechanism may be actuated in response to those signals to control mechanical diversion of the culls. Although the articles to be diverted by the present apparatus are hereinafter referred to as culls, it is understood, of course, that second-grade fruit or other computer selected fruit may also be included. The ejector mechanism may comprise a plurality of solenoid-controlled pistons, the solenoids being actuated by signals from output relays. Such prior art ejector mechanisms, however, suffer serious deficiencies. For example, with singulator conveyor speeds approaching 30" per second and rollers spaced about 3" apart (for lemons, for example), it is often necessary that the ejector be capable of consecutively diverting a series of lemon culls at a rate of about 10 per second without compounding their background injuries. Piston rods of existing diverters are caused to impact the fruit directly for deflection thereof from the pack line. For lemons, these piston rods normally travel in excess of 2". Prior art ejector mechanisms employing such long stroke piston rods are incapable of deflecting fruit at a sufficiently rapid rate. Even at these comparatively low diverting rates, the long piston rods would often bend, necessitating shut-down of the entire pack line. Efforts to shorten the stroke length of the piston rods to thereby increase the diversion rate of the ejectors were unsatisfactory, since some lemons invariably become positioned too close to or removed from the resilent bumper on the working end of the reciprotating piston rod to either bruise the lemons further or fail to deflect the lemons onto the cull conveyor belt.
The present apparatus is capable of rapidly, reliably, and gently diverting culls from pack lines. The apparatus employs a solenoid-controlled piston as did the prior art ejectors, but the piston stroke may be less than 1/2 shorter in length, thus providing exceptionally rapid cycling times with only the slightest chance of piston rod bending even after completion of 40,000,000 cycles.
Briefly, the present article diverter includes a first pivot point which defines the point at which an ejector lever pivots with respect to an ejector lever mount supporting the ejector lever, a solenoid-actuated air or hydraulic piston pivotally mounted to the ejector lever mount at a point distant from the first pivot point to comprise a second pivot point. The piston rod of the piston is affixed to a bearing member which is pivotally mounted to the ejector lever at a point intermediate the first pivot point and a resilient pad secured to the ejector lever at a point distant from said first pivot point to comprise a third pivot point. Thus, upon a short diverting stroke of the piston rod, the resilient pad is caused to swing in a relatively long arcuate path to impact offending fruit from the pack line. The retraction stroke of the piston rod returns the resilient pad and ejector lever to its original position along the same arcuate path. By adjusting the third pivot point slightly toward or away from the first pivot point, the arcuate length and speed of the diverting and retraction strokes can be readily controlled consonant with the size, density, injury proneness, and the like, of the fruit to be diverted.